1. Field of the Invention
The invention relates to a memory card or chip card reader system and more particularly to a card reader that can be connected to a microcomputer. Such a reader can be applied to the reading of synchronous memory type cards, for example telephone cards, as well as to the reading of the bank card types known as chip cards.
2. Discussion of the Related Art
The many readers that are in existence have the common feature of operation achieved by a microprocessor of their own that manages the sampling of an input/output line of the card and the associated transmission protocol. Furthermore, the microprocessor of the reader also provides for the interfacing with the microcomputer. Each reader therefore has a microprocessor whose design is developed to a greater or lesser extent and has a considerable effect on the cost of the reader.
The cards accepted by each reader and the protocols of transmission to the microcomputer are fixed in the microprocessor of the reader. This microprocessor finds out whether it can process the card presented to it and, together with the microcomputer, decides on the transmission protocol.
The connection of a card reader to the microcomputer is done by means of a connector or port on the microcomputer that is reserved solely for the connection of the reader. This port may be designed for serial or parallel transmission. This therefore necessitates a specific port for the card reader on each microcomputer. This is a drawback because it is useful, for reasons of cost or flexibility of use, to reduce the number of ports in the microcomputer.